Flexible coupling

ABSTRACT

A flexible coupling including a pair of generally coaxially aligned hub members, each hub secured to a circular cable to transmit radial forces. The hub members each have a pair of opposed radial arms and the cable is secured to the arms by clamps. The radius of the circular cable is preferably less than the length of the arms and the clamps are hook-shaped, with the shank portion of the hook parallel to the axis of the hubs, to secure the cable radially inwardly of the distal ends of the arms.

UllltGd States Patent 1 Strain 1 May 15, 1973 [76] Inventor:

[54] FLEXIBLE COUPLING William E. Strain, 503 Shirley Drive, Birmingham,Mich. 48009 22 Filed: Sept. 21, 1971 211 Appl.No.: 182,340

[52] US. Cl ..267/148 [51] Int. Cl. ..F16f 15/10 [58] Field of Search..267/l48 [56] References Cited UNITED STATES PATENTS 3,204,943 9/1965Kerley, Jr ..267/148 Primary Examiner-James B. Marbert Attorney Cullen,Settle, Sloman & Cantor [57] ABSTRACT A flexible coupling including apair of generally coaxially aligned hub members, each hub secured to acircular cable to transmit radial forces. The hub members each have apair of opposed radial arms and the cable is secured to the arms byclamps. The radius of the circular cable is preferably less than thelength of the arms and the clamps are hook-shaped, with the shankportion of the hook parallel to the axis of the hubs, to secure thecable radially inwardly of the distal ends of the arms.

10 Claims, 4 Drawing Figures PATENTED 3,733,066

4I\L22/-5O/2O 52 17" 56 4O r24 38 26 8 4a 3 3 52 j 30 3o INVENTORWILLIAM E. STRAIN.

BY I

CULLEN, SETTLE, swMAN a CANTOR ATT'YS.

FLEXIBLE COUPLING FIELD OF THE INVENTION The flexible coupling of thisinvention is adapted to transmit radial forces, including rotation,while permitting axial and radial misalignment between the driving anddriven members. The coupling is also capable of absorbing vibration andshock loading and minimizing backlash, which is a problem in couplingdesign.

One of the couplings disclosed in the prior art, U.S. Pat. No.3,204,943, attempts to solve these problems by utilizing a plurality oflinear cable sections joined by collars into a rigid polygonal loop. Apair of opposed plates are secured within the loop to transmit thedesired radial forces. An object of the present invention is to providea coupling which is simpler in design than this structure and moreefficient in operation.

The coupling of this invention includes a pair of generally coaxiallyaligned hub members adapted to transmit the radial loading having aplurality of radially extending, equally spaced arms adjacent one end. Acircular cable, such as the twisted monofiliment cable disclosed in theabove referenced patent, islocated between the arms of the hubs. Thediameter of the cable is preferably smaller than the circular projectionof the arms. The hub members are positioned on opposite sides of thecable, in spaced relation, with the arms of one hub member bisecting theangle defined between the arms of the opposed hub member. The cable isclamped to the arms by a clamping means provided on each of the armsradially inwardly from the distal end of the arms.

In the preferred embodiment of the flexible coupling of this invention,the clamping means is a hook-shaped clamp having a shank portionextending generally parallel to the axis of the hub members and ahook-portion which overlies the opposed surfaces of the arms. The armsmay also be provided with a semi-circular groove which receives thecable to securely vclamp the hub members on the cable. in spacedrelation to permit transmission of radial forces while permitting axialand radial misalignment between the driving and driven hub member.

In the disclosed embodiment of the flexible coupling, the cable isprovided with a plurality of generally cylindrical sleeves which areequally spaced on the cable. The sleeves are preferably formed of amaterial softer than the cable and are secured on the cable bycompressing the sleeves. The sleeves provide accurate alignment of thehub members, which is important for uniform flexing and dampening of thevibration and shock forces, and to prevent wear of the cable.

In the preferred embodiment of the flexible coupling of this invention,the hub members are spaced axially, by the clamping members,sufficiently to provide substantial flexibility for correction ofmisalignment between the hub members. In the disclosed embodiment, theradius of the circular cable is less than the diameter of thecylindrical hub portions and the hub members are spaced axially adistance nearly equal to the radius of the hub portions, providingsubstantial flexibility and minimizing backlash. The disclosedembodiment of the flexible coupling is simple to assemble anddisassemble and is relatively inexpensive compared to other all metalflexible couplings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a. top elevation of oneembodiment of the flexible coupling of this invention;

FIG. 2 is a side elevation of the flexible coupling shown in FIG. 1; 1

FIG. 3 is a side cross sectional view of the clamping means utilized inthe flexible coupling shown in FIG. 1, in the direction of view arrows3-3; and

FIG. 4 is a perspective top view of the cable assembly utilized in theflexible coupling shown in FIGS. 1 and DESCRIPTION OF THE PREFERREDEMBODIMENT The flexible coupling 20 disclosed in FIGS. 1 to 4 includes apair of hub members 22, a circular cable assembly 24 disposed betweenthe hub members and four clamping means 26 securing the opposed hubmembers to the cable assembly 24.

The hub members 22 each include a generally cylindrical hub portion 28and a pair of radially extending arms 30 adjacent the opposed ends ofthe hub members. The hub members are adapted to transmit radial loads,including rotation, from the driving hub member to the driven hubmember. The disclosed embodiment of the hub members include acylindrical bore 32 hav-- ing a key-way slot 34 and set-screw 36 whichis adapted to receive a conventional shaft for imparting radial motion.It will be understood that the bore 32 may also be threaded to receivethe driving or driven shaft or the shaft may be integral with the hubdepending upon the particular application for the coupling.

The radially extending arms 30,-in the disclosed embodiment of the hubmember, each include a pair of reinforcing web portions 38 which mergeinto the axial boss portions 40 on the hub portion of the member. Aflange 41, having an arcuate semicircular groove 42 configured toreceive the cable assembly is provided on each of the opposed ends ofthe arm portions, and an aperture 44 is disposed through the flanges toreceive the clamping means 26, as shown in FIG. 3.

The clamping means shown in FIG. 3 includes a hook-shaped clamp 46having a shank portion 48, which is received through the aperture 44 inthe hub member arms and a hook-shaped portion 50 which is adapted tooverlie the semicircular groove 42 in the arms and secure the cableassembly 23. .The shank portion, in the disclosed embodiment, isthreaded to receive a nut 52 which biases the hook portion toward thearm and securely retains the cable.

The disclosed embodiment of the cable assembly 24, as shown in FIG. 4,includes four equally spaced cylindrical sleeves 54 which are receivedin the semicircular grooves 42 in the arms of the hub members toaccurately position the arm portions on the cable and prevent wear ofthe cable. The sleeves each include a pair of opposed flanged portions56 which locate the sleeves in the flange portions. The sleeves arepreferably formed of a material softer than the cable and are compressedon the cable to prevent axial movement of the sleeves.

The dimensional relation of the flexible coupling of this invention isimportant to provide maximum allowance for axial and radial misalignmentof the hub members. The disclosed hub members are each adapted toreceive a shaft for transmission of radial forces, such as the drivingand driven shafts of a machining apparatus. One of the hubs may receivethe motor shaft, for example, and the opposed hub may receive the drivenshaft of the machine. In such applications, it is generally difficult toaccurately align the shafts and eliminate vibrational forces which maybe detrimental to the machining apparatus. The coupling of thisinvention is capable of transmitting the intended radial or rotationalforces, although the shafts are not accurately aligned andsimultaneously dampen vibrational forces. Further, and most important,the coupling of this invention is not subject to heat deterioration,because all of the parts may be metallic, and the coupling may be easilyassembled and disassembled at the coupling site.

The preferred dimensional relationship of the coupling includes thespace provided between the hub members which permits compensation forsubstantial misalignment between the axes of the hub members.

The spacing in the disclosed embodiment is provided I by the clampingmeans 26, wherein the shank portion 48 of the clamp is generallyparallel to the axis of the hub members, in the relaxed position. Theradius of the cable may thus be less than the length of the arms, suchthat the cable is located radially inwardly of the distal ends of thearms. Stated another way, the diameter of the cable is smaller than thediameter a circle circumscribing the distal ends of the arm portions ofthe hub. The hub members are spaced axially a distance nearly equal tothe radius of the hub portions, providingsubstantial flexibility andminimizing backlash.

It will be understood that the materials of the elements of the couplingmembers will, in part, depend upon the particular application of thecoupling. The hub members may be cast from any suitable material,including aluminum or steel. Alternatively, the hub members may bemachined. The clamps may be formed from forged steel, for example, andthe cable may be a suitable resilient twisted monofiliment cable, suchas stainless steel. As described above, the sleeves 54 are preferrablyformed of a material softer than the cable, such as brass, aluminum orcopper. Where the cable is a continuous circular cable, the sleevesserve to accurately position the arms on the cable and prevent wear, asdescribed above. The sleeves may also be utilized to secure the ends ofa cable member where the cable is not continuous.

The disclosed embodiment of the flexible coupling of this invention isassembled by disposing the cable assembly into the semicircular grooves42 in the arm portions of one of the hub members. The clamp 46 is thenreceived through the aperture 44, with the hook portion 50 overlying thecable, and the cable is secured by tightening the nut 52 on the threadedshank portion of the clamp. The opposed hub member is secured to thecable in a like manner.

In the preferred embodiment, the cable assembly includes a plurality ofequally spaced sleeves 54 equal in number to the total number of arms 30on the hub members. In the disclosed embodiment, each hub memberincludes two oppositely disposed arm portions and the cable includesfour sleeves spaced ninety degrees on the circumference of the cable. Itwill be understood however that the hub member may include a greaternumber of arms, in which case the arms are preferably equally spacedabout the circumference of the cylindrical hub portion 28 and the hubsare assembled with the arms of one hub member bisecting the angledefined between the arms of the opposed hub member. The sleeves thusaccurately align the arms on the cable and provide the other advantagesdescribed above. The coupling may be disassembled merely by removing theclamping means.

I claim:

1. A flexible coupling, comprising:

a. a pair of generally coaxially aligned hub members adapted to transmitradial loads,

b. each of said hub members having a plurality of radially extending,equally spaced arms adjacent one end of the hub member,

c. a circular cable having a diameter smaller than the circularprojection of said arms located between said arms and generallycoaxially aligned with said hub members,

d. said hub members positioned on opposite sides of said cable, in spacerelation, with said arms of one hub member bisecting the angle definedbetween the arms of the opposed hub member, and,

e. clamping means on each of said arms adapted to clamp said cable tosaid arms radially inwardly of the distal end of said arms.

2. The flexible coupling defined in claim 1, characterized in that saidclamping means includes a plurality of hook-shaped clamps one extendingfrom each of said arms radially inwardly of the distal end, clampingsaid cable against said arms.

3. The flexible coupling defined in claim 2, characterized in that saidhook-shaped clamps each include a shank portion extending generallyparallel to the axis of said hub members, toward the opposed hub member,to secure said hub members in spaced relation.

4. The flexible coupling defined in claim 1, characterized in that saidcable includes a plurality of equally spaced, generally cylindricalsleeves, each of said clamping means secured to one of said sleeves,said sleeves formed of a softer material than the cable and compressedagainst said cable to prevent axial movement.

5. A flexible coupling, comprising:

a. a pair of generally coaxially aligned hub members adapted to transmitradial loads,

b. each of said hub members having a pair of radially extending opposedarms adjacent one end,

c. a circular cable having a radius smaller then the length of said armslocated between said arms and generally coaxially aligned with said hubmembers,

d. said hub members positioned on said cable, in spaced relation, withsaid arms of one hub member perpendicular to the arms of the opposed hubmember, and,

e. a generally hook-shaped clamp on each of said arms, including a shankportion generally parallel to the axis of said hub members, secured tosaid arms and a hook portion receiving said cable and securing saidcable inwardly of the distal end of said arms.

6. The flexible coupling defined in claim 5, characterized in that saidarms each include an arcuate semicircular groove inwardly of the distalend of said arms which receives said circular cable, and said hookporceives a nut to bias the hook portion against said cable.

8. The flexible coupling defined in claim 5, characterized in that saidcircular cable is a continuous, spirally wound monofiliment metal cable.

9. The flexible coupling defined in claim 5, characterized in that saidcable includes four equally spaced, generally cylindrical sleeves, eachof said clamping means secured to one of said sleeves, said sleevesformed of a softer material than said cable and compressed against saidcable to prevent axial movement.

10. A flexible coupling, comprising:

a. a pair of generally cylindrical coaxially aligned hub members adaptedto transmit rotary loads,

' b. each of said hub members having a pair of radiallyextending-opposed arms adjacent one end,

c. a circular cable having a diameter smaller than the v arms inwardlyof the distal end of said arms.-

1. A flexible coupling, comprising: a. a pair of generally coaxiallyaligned hub members adapted to transmit radial loads, b. each of saidhub members having a plurality of radially extending, equally spacedarms adjacent one end of the hub member, c. a circular cable having adiameter smaller than the circular projection of said arms locatedbetween said arms and generally coaxially aligned with said hub members,d. said hub members positioned on opposite sides of said cable, in spacerelation, with said arms of one hub member bisecting the angle definedbetween the arms of the opposed hub member, and, e. clamping means oneach of said arms adapted to clamp said cable to said arms radiallyinwardly of the distal end of said arms.
 2. The flexible couplingdefined in claim 1, characterized in that said clamping means includes aplurality of hook-shaped clamps one extending from each of Said armsradially inwardly of the distal end, clamping said cable against saidarms.
 3. The flexible coupling defined in claim 2, characterized in thatsaid hook-shaped clamps each include a shank portion extending generallyparallel to the axis of said hub members, toward the opposed hub member,to secure said hub members in spaced relation.
 4. The flexible couplingdefined in claim 1, characterized in that said cable includes aplurality of equally spaced, generally cylindrical sleeves, each of saidclamping means secured to one of said sleeves, said sleeves formed of asofter material than the cable and compressed against said cable toprevent axial movement.
 5. A flexible coupling, comprising: a. a pair ofgenerally coaxially aligned hub members adapted to transmit radialloads, b. each of said hub members having a pair of radially extendingopposed arms adjacent one end, c. a circular cable having a radiussmaller then the length of said arms located between said arms andgenerally coaxially aligned with said hub members, d. said hub memberspositioned on said cable, in spaced relation, with said arms of one hubmember perpendicular to the arms of the opposed hub member, and, e. agenerally hook-shaped clamp on each of said arms, including a shankportion generally parallel to the axis of said hub members, secured tosaid arms and a hook portion receiving said cable and securing saidcable inwardly of the distal end of said arms.
 6. The flexible couplingdefined in claim 5, characterized in that said arms each include anarcuate semicircular groove inwardly of the distal end of said armswhich receives said circular cable, and said hook portion of the clampoverlies said grooves to secure the cable therein.
 7. The flexiblecoupling defined in claim 6, characterized in that the shank portion ofeach of said clamps is received through one of said arms and threadablyreceives a nut to bias the hook portion against said cable.
 8. Theflexible coupling defined in claim 5, characterized in that saidcircular cable is a continuous, spirally wound monofiliment metal cable.9. The flexible coupling defined in claim 5, characterized in that saidcable includes four equally spaced, generally cylindrical sleeves, eachof said clamping means secured to one of said sleeves, said sleevesformed of a softer material than said cable and compressed against saidcable to prevent axial movement.
 10. A flexible coupling, comprising: a.a pair of generally cylindrical coaxially aligned hub members adapted totransmit rotary loads, b. each of said hub members having a pair ofradially extending opposed arms adjacent one end, c. a circular cablehaving a diameter smaller than the circular projection of said armslocated between said arms and generally coaxially aligned with said hubmembers, d. said cable having four equally spaced cylindrical sleevesreceived on said cable and secured thereto, and e. a generallyhook-shaped clamp on each of said arms including a shank portiongenerally parallel to the axis of said hub and a hook portion receivingsaid cable and clamping said cable against said arms inwardly of thedistal end of said arms.